Index plate



Nov. 8, 1927.

- 1,648,034 F. UNGERER INDEX PLATE FiledFeb. 18, 1927 2 Sheets-Sheetl Ey 4L. 7750671 for' eren Nov. 8, l1927'.

F. UNGERER INDEX PLATE Filed Feb. 18, 1927 2 Sheets-Sheet 2 Patented Nov. 8, 1927.

FRITZ UNG-EBEE, OF PFORZHEIM, GERMANY.

INDEX PLATE.

Application med February 18, 1927, Serial No. 169,261, and in Germany .'l'cvemher 23, 1925.

The present invention has reference to im- )rovements in dividing or index plates. or heads and relates more particularlyto 1mproved means for adjusting and locklng the indexing members thereof.

The worin wheel mounted on the work shaft or arbor of the index heads in the known art generally will be found provided with forty teef-hand meshes wlth .ag slnglethread worm upon the shaft of which latter is mounted the crank member supportlng theV index pin. Upon the worm' being rotated by the crank through a 'single complete revolution, the worm wheelg with its,v shaft, obviousl will make one-fortieth of a revolut1on. If, or instance, a wheel of ten teeth 1s to be milled out, the worm must he rotated four times for each tooth. It is immaterial which annular row of graduation holes in the fixed `index member is used. The index pin is inserted again into the starting hole after the four revolutions of the crank. If, however, for instance a wheel is to be milled presenting fourteen teeth, then each time revolutions of the crank are required. This is possible in the following manner: The crank is turned twice around, whereupon a partial revolution is made corresponding to the fraction 6/7. For this pur ose the index in is adjusted on the circle o holes, whose iiole number is a multiple of 7, for instance 28. After conclusion of the two complete revolutions the operator counts 'from the starting hole 28/7 x 6:4 x 4=24 divisions, md then inserts the pin into the th hole. For avoiding the bothersome counting of the graduation holes on turning the-crank there tre generally provided two pointers or sto s n concentric relation with the worm sha t, ',he angular interspacing of which stops can )e adjusted in accordance with the required )artial'rotation of the crank. These stops- )resent radially directed contact edges re 'Psentin the legs of the respective operative ingle. eign the present example the angular pacing of these two stop members, or more )recisey stop edges, would have to be 24/28 f a complete revolution. If then one of hese stop edges tangentiallyextends as tarting edge along the starting hole, the :ontact edge of the other stop, serving as :ontact edge for the index pin, will tangen'v ially cooperate with that hole of the 28-hole circle which is 24 divisions away from the starting hole.- For setting a division the lindex pin is moved from the starting edge tov the contact edge of thesecond stop member, and is then moved. twice around and finally inserted into the hole on the near edge of this second stop. The milling operation is now started, during which the stops are adjusted on the plate inthe sense of the crank rotation, until the starting edge again contacts with the locked index pin.

The known plate stops are provided with I bushings riding'on the worm shaft, which bushinffs are pressed against one another anl the index plate by means of a spring-controlled friction plate for preventing inadvertent dis lacement of these stops. Since, however, t e stops must be adjusted after each crank movement, their relative fixation merely by friction is insufficient for proper operation. If the operator during the adjusting movementfails to withdraw the index pin completely out of the domain of the stops, the pin is apt to .contact with the latter, which would cause disturbing relative displacement of the stops, which an attentive operator may notice andcorrect by careful re-adjustment. If, however, he 'fails to notice this undesired displacement of the stop or stops, then the work piece will have to be discarded inthe end as waste.

It is the object of the present invention to do away with these just recited drawbacks attaching to the use of the dividing devices of prior design, and the invention resides essentially in the feature that both stop mem-v bers are adjustable and lockable on acommon annular member which is concentrical with the index plate and relativelyrotatable thereabout.

My invention will best be understood when deseribedin connection with the accompanying drawings, in which Fior. l is a side view of the new arrangement; tFig. 2 is a crosssection therethrough; Fig. 3 is a top view, and Fig. 4 a section through 'a modified index pin; Figs. 5 views of a modification, of which Fig. 7 is a cross-section; Fig. 8 is a fragmentary crossy section through still another modification.

Referring firstto Figs. 1 and 2, theholed index plate 3 is fixed on the hollow boss l of the fixed index head 2. The circumferential face 30 ofthe plate 3 is of convex confirmation for seating the correspondingly concaved enlargements 4 of the collar 5, which latter is of spring character andissprung onto and 6 show front and rear the part 30, being thus safeguarded against lateral slipping-off, but it can readil be rotated on and about the plate 3. nto the outer circumference of the collar 5 is sunk the dove-tail groove 6 for receiving the flared head 70 of the screw pins 7 of the bracket stops 9 and 10. The latter are secured to the collar 5 by these pins 7 and the thumb nuts 8. Within the boss 1 is journaled the worm shaft 11 which, in well known manner, is rotated by means of the crank member 13 from which extends inwardlynear its one extremity the index pin 12. In order to adjust this pin to the radii of the several circles of holes, only one of which circles is shown here, there is provided in' the member 13 the slot 14 in'to which extends the squarely contracted end 15 of the shaft 11. The nut 16 serves for locln'ng the member 13, which latter may conveniently be provided with a handle 17, as shown. The index pin 12 can be moved out of the domain of the plateI 3 and the stops 9 and 10, against the pressure of its spring 18, by a pull on its knob 19. The operator will generally rotate the crank member 13 by thisl knob, as the most convenient way, b ut if a .separate handle 17 is provided, there is then preferably provided an intermediate member 20 (Fig. 4) for retaining the pinl 12 in 'its temporarily retracted position. f

The operation of the described mechanism ,is as follows z-Suppose a milling operation requiresl a crank member movement of 3 17 /22 revolutions, and the index pin 12 is in hole a (Fig. 1) the starting edge 90 of stop 9 contacts with the index pin and forms between itself and the contact edge 100 of the stop 10 an angle of 17 /22 of a complete revolution, that is to say, the edges 90 and 100 have initially been fixed on the collar 5 in such manner that they are spaced apart (in clockwise sense) the distance of 17 divisions, measured on the 22-hole circle, as shown in Fig. 1. If now the milling operation has been ended and there is required an adjustment to 3 17 /22 revolutions, the index pin l2 is withdrawn from the hole a, is then swun around to the stop edge 100, and then still urther through three complete revolutions, and finally dropped into the hole b. During the subsequent milling operation the stops 9 and 10 are adjusted. For this purpose provision is made to rotate the collar 5 about the plate 3 in clockwise direction without the angular distance between the stops being altered. The rotation of the collar 5 cannot take p'lace by the nut 8 of stop 10, since by pullingor pressing on this nut 8 the elastic collar would onl be pressed the harder onto its annular seat, ut with the nut 8 of stop 9 as handle, the rotation of the collar can readil be eifected in the direction ofthe arrow in ig. 5, until the edge 90 contacts with the index pin 12 in the hole b,

which then represents a partial revolution of 17 /22.' At the end of the operation the crank 13 is again relatively shifted, after pin 12 has been retracted, to the contactl edge 100, and then a further three complete revolutions, when the pin is dropped into the hole c (Fig. 6), and so on.

An inadvertent relative displacement of the two stop members 9 and 10 cannot occur, since -they are firmly locked on the collar 5 by their nuts 8. Also, an unintended displacement of the collar 5 with its stops 9 and 10 on the plate 3, by the index pin 12 striking the edge 100 during the setting of the parts need not be feared, since each such knock againstv the stop l0 tends to press the collar 5 all the harder onto its seat member. If by insuflicient lift of the pin 12 the parts have contracted, the operator merely lifts the pin 12 out of contact with the stops 9 and 10 in its advance movement.

In order to make a collision between 1n 12 and stop 9 impossible, an eventuality which might cause inadvertent displacement of the collar on its seat, I may arrange, according to the modified embodiment shown in Figs. 5, 6 and 7, the stop 9 upon the rear face of the plate 3 and extend the pin 12 so far through the latter that, on adjustment of the stops 9 and l0, the former makes contact with the pin at the rear of the plate 3 (Fig. 7). In this manner, also, the stops 9 and 10 cannot be confused.

On exchange of index plates and when adjusting the angular distance between the stops, the invention shows important advantages over prior constructions, as readily apparent. VThe collar 5 can easily be removed from its seat by a short jerk on one of the nuts 8 in lateral direction. In the known art the angular stop member distance can be adjusted only after the crank member has been removed, each stop being separately held by hand on the plate. In the present instance the crank member is not removed, so

that the index pin can be used as contact I member for one of the stops.

Instead of arranging the collar 5 with its stop members 9 and 10 `for sliding movement upon the plate 3, it may also be slidably mounted, according to the modification shown in Fig. 8, on a separate member 21, or the like, arranged parallel of the plate 3 in the rear thereof, the stop members being so designed and lockable on the collar 5 that they can be adjusted and operate in the manner above described.

Vhat I claim is:

1. In a dividing mechanism of the character set forth, in combination with a fixed machine head including a plate member presenting at least one circle of axially extending graduation holes and a worm shaft rotatable in said head and extendin through said plate, a crank memberfixe on said shaft for rotation therewith in front of said holed plate, a snap index pin on said crank member for selective cooperation with said plate holes, a collar mounted for frictional circumferential rotation on said holed plate, stop members on said collar for cooperation with said index pin, and means associated with said stop members for allowing their individual adjustment on said collar.

2. In a dividing mechanism of the chal'- acter set forth, in combination with a fixed machine head including a holed plate and a worm shaft vrotatably extending therethrough, a crank member lockable on-said shaft for throw alteration and for rotation therewith in front of said holed plate, -a snap pin at the operative crank end for selective cooperation with the holes in said plate, and means for temporarily holding said snap pin in retracted position, an elastic collar clampingly mounted on said holed plate for relative circumferential displacement thereon, stop members adjustable on said collar, and means for individually locking said stop members on' said collar, and said locking means also designed for increasing the clamping pressure between collar and supporting plate on contra-directed movementof said stop members.

3. In a dividing mechanism of the character set forth, in combination with a fixed machine head including a holed plate and a' worm shaft rotatablyV extending therethrough, a crank member on said shaft for rotation therewith in front of said holed plate, a snap pin on said crank member for selective coopera-tion with the holes in said plate, a carrier member mounted'on said holed plate for circumferential displacement thereon, and a rearand a front stop member independently adjustably lockable on said carr1er member and respectively extending radially across the front and rear faces of said plate, the holes of the latter extending clear through for allowing said snap pin to extend therethrough beyond the rear face of the plate for cooperation with the respec* tive rear stop.

4. In a dividing mechanism of the character set forth, in combination with a fixed machine head including a holed plate and a worm shaft rotatably extending therethrough, a crank member lockable on said shaft, an index pin on said crank member, relatively adjustable stop members for alternate cooperation 'with said index pin, a carrier for said stop members, and fixed supporting means in ependent of said holed plate for said carrier, for allowing concentric displacement of the latter relative to said holed plate.

' In testimony whereof I affix my signature.

FRITZ UN GERER. 

